| import { root } from '../util/root'; |
| import { Observable } from '../Observable'; |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @extends {Ignored} |
| * @hide true |
| */ |
| export class PromiseObservable extends Observable { |
| constructor(promise, scheduler) { |
| super(); |
| this.promise = promise; |
| this.scheduler = scheduler; |
| } |
| /** |
| * Converts a Promise to an Observable. |
| * |
| * <span class="informal">Returns an Observable that just emits the Promise's |
| * resolved value, then completes.</span> |
| * |
| * Converts an ES2015 Promise or a Promises/A+ spec compliant Promise to an |
| * Observable. If the Promise resolves with a value, the output Observable |
| * emits that resolved value as a `next`, and then completes. If the Promise |
| * is rejected, then the output Observable emits the corresponding Error. |
| * |
| * @example <caption>Convert the Promise returned by Fetch to an Observable</caption> |
| * var result = Rx.Observable.fromPromise(fetch('http://myserver.com/')); |
| * result.subscribe(x => console.log(x), e => console.error(e)); |
| * |
| * @see {@link bindCallback} |
| * @see {@link from} |
| * |
| * @param {PromiseLike<T>} promise The promise to be converted. |
| * @param {Scheduler} [scheduler] An optional IScheduler to use for scheduling |
| * the delivery of the resolved value (or the rejection). |
| * @return {Observable<T>} An Observable which wraps the Promise. |
| * @static true |
| * @name fromPromise |
| * @owner Observable |
| */ |
| static create(promise, scheduler) { |
| return new PromiseObservable(promise, scheduler); |
| } |
| _subscribe(subscriber) { |
| const promise = this.promise; |
| const scheduler = this.scheduler; |
| if (scheduler == null) { |
| if (this._isScalar) { |
| if (!subscriber.closed) { |
| subscriber.next(this.value); |
| subscriber.complete(); |
| } |
| } |
| else { |
| promise.then((value) => { |
| this.value = value; |
| this._isScalar = true; |
| if (!subscriber.closed) { |
| subscriber.next(value); |
| subscriber.complete(); |
| } |
| }, (err) => { |
| if (!subscriber.closed) { |
| subscriber.error(err); |
| } |
| }) |
| .then(null, err => { |
| // escape the promise trap, throw unhandled errors |
| root.setTimeout(() => { throw err; }); |
| }); |
| } |
| } |
| else { |
| if (this._isScalar) { |
| if (!subscriber.closed) { |
| return scheduler.schedule(dispatchNext, 0, { value: this.value, subscriber }); |
| } |
| } |
| else { |
| promise.then((value) => { |
| this.value = value; |
| this._isScalar = true; |
| if (!subscriber.closed) { |
| subscriber.add(scheduler.schedule(dispatchNext, 0, { value, subscriber })); |
| } |
| }, (err) => { |
| if (!subscriber.closed) { |
| subscriber.add(scheduler.schedule(dispatchError, 0, { err, subscriber })); |
| } |
| }) |
| .then(null, (err) => { |
| // escape the promise trap, throw unhandled errors |
| root.setTimeout(() => { throw err; }); |
| }); |
| } |
| } |
| } |
| } |
| function dispatchNext(arg) { |
| const { value, subscriber } = arg; |
| if (!subscriber.closed) { |
| subscriber.next(value); |
| subscriber.complete(); |
| } |
| } |
| function dispatchError(arg) { |
| const { err, subscriber } = arg; |
| if (!subscriber.closed) { |
| subscriber.error(err); |
| } |
| } |
| //# sourceMappingURL=PromiseObservable.js.map |